Drawworks JC28KIII Easy Worn Parts

1

GB/T288-1994

Bearing

High-carbon chromium bearing steel (GCr15) with quenching & tempering treatment (HRC 60-64)

1. Lubrication failure (contaminated or insufficient grease); 2. High vibration causing metal fatigue; 3. Misalignment leading to uneven load distribution (violates GB/T288-1994 alignment requirements).

1. Use lithium-based grease (NLGI 2) compliant with GB/T7324-2010, replenish every 3 days; 2. Inspect alignment monthly (radial runout ≤0.03mm); 3. Replace if temperature exceeds 80℃ during operation (GB/T288-1994 safety limit).

2

GB/T276-1994

Bearing

High-carbon chromium bearing steel (GCr15SiMn) for enhanced toughness

1. Contamination by drilling mud/dust entering the bearing cavity; 2. Overload beyond GB/T276-1994 rated dynamic load; 3. Improper installation causing raceway damage.

1. Ensure sealing components are intact to prevent contamination; 2. Do not exceed rated load (varies by size, refer to GB/T276-1994 table); 3. Use a press-fit tool during installation (avoid hammering).

3

GB/T13781-1992

Bearing

GCr15 bearing steel with corrosion-resistant coating

1. Corrosion from humid/dusty drilling environments; 2. Long-term continuous operation causing fatigue wear; 3. Grease degradation due to high operating temperature.

1. Clean bearing surfaces daily to remove mud/dust; 2. Replace grease every 6 months (or earlier if discolored); 3. Apply anti-rust grease quarterly in coastal/humid areas.

4

GB/T13781-1992

Bearing

GCr15 bearing steel with corrosion-resistant coating

1. Corrosion from humid/dusty drilling environments; 2. Long-term continuous operation causing fatigue wear; 3. Grease degradation due to high operating temperature.

1. Clean bearing surfaces daily to remove mud/dust; 2. Replace grease every 6 months (or earlier if discolored); 3. Apply anti-rust grease quarterly in coastal/humid areas.

5

GB/T13781-1992

Bearing

GCr15 bearing steel with corrosion-resistant coating

1. Corrosion from humid/dusty drilling environments; 2. Long-term continuous operation causing fatigue wear; 3. Grease degradation due to high operating temperature.

1. Clean bearing surfaces daily to remove mud/dust; 2. Replace grease every 6 months (or earlier if discolored); 3. Apply anti-rust grease quarterly in coastal/humid areas.

6

GB/T281-1994

Bearing

GCr15SiMn bearing steel with precision grinding (grade P6)

1. High-speed rotation causing raceway wear; 2. Misalignment leading to edge loading; 3. Lack of lubrication during start-up (dry friction).

1. Pre-lubricate bearings before start-up; 2. Inspect rotational speed monthly (not exceeding GB/T281-1994 limit); 3. Replace if abnormal noise persists after lubrication.

7

GB/T276-64

Bearing

Carbon chromium steel (GCr9) for medium-load applications

1. Metal fatigue from cyclic load during drilling; 2. Contamination causing abrasive wear; 3. Outdated standard (GB/T276-64) parts with inherent material limitations.

1. Inspect weekly for wear (gap ≤0.02mm); 2. Replace with genuine GB/T276-64 parts (not modern substitutes); 3. Avoid overloading (adhere to GB/T276-64 load ratings).

1

GB/T3452.1-1982

O ring

Nitrile rubber (NBR 70 shore A) with oil-resistant coating (compliant with GB/T5574-2008)

1. High temperature (exceeding 120℃) causing rubber aging; 2. Abrasion from sharp component edges; 3. Chemical erosion from drilling fluid additives.

1. Avoid contact with sharp edges during installation (use a rubber sleeve); 2. Keep operating temperature below 120℃ (GB/T3452.1-1982 limit); 3. Replace every 3 months (or earlier if hardening/cracking is found).

2

GB/T3452.1-1982

O ring

Nitrile rubber (NBR 70 shore A) with oil-resistant coating (compliant with GB/T5574-2008)

1. High temperature (exceeding 120℃) causing rubber aging; 2. Abrasion from sharp component edges; 3. Chemical erosion from drilling fluid additives.

1. Avoid contact with sharp edges during installation (use a rubber sleeve); 2. Keep operating temperature below 120℃ (GB/T3452.1-1982 limit); 3. Replace every 3 months (or earlier if hardening/cracking is found).

3

GB/T13781-1992

Oil seal

NBR rubber seal lip + carbon steel skeleton (GB/T13781-1992 standard thickness)

1. Wear from shaft surface scratches; 2. Grease contamination causing seal lip hardening; 3. Vibration leading to skeleton deformation.

1. Inspect shaft surface for scratches before installation (polish if needed); 2. Use clean, compatible grease (avoid mixed grease types); 3. Replace if oil leakage exceeds 5ml/24 hours.

4

Mechanical seal

Mechanical seal

Silicon carbide (SiC) stationary ring + carbon graphite rotating ring + stainless steel (304) spring

1. Dry running causing seal face damage; 2. Contamination by solid particles in lubricant; 3. Spring fatigue from long-term vibration.

1. Ensure sufficient lubrication before start-up (no dry running); 2. Install a 10μm filter to prevent solid particles; 3. Inspect seal face monthly for scratches (replace if found).

1

JC28A-02-07

Braided brake block

Asbestos-free friction material (aramid fiber + resin) + steel backing plate (Q235)

1. Frequent heavy braking causing friction wear; 2. High temperature (exceeding 300℃) causing material degradation; 3. Misalignment leading to uneven wear.

1. Avoid excessive braking (use auxiliary brakes for heavy loads); 2. Inspect thickness weekly (replace if ≤5mm); 3. Adjust alignment to ensure full contact with brake drum (no edge wear).

2

JC28A-02-08

Braided brake block

Asbestos-free friction material (aramid fiber + resin) + steel backing plate (Q235)

1. Frequent heavy braking causing friction wear; 2. High temperature (exceeding 300℃) causing material degradation; 3. Misalignment leading to uneven wear.

1. Avoid excessive braking (use auxiliary brakes for heavy loads); 2. Inspect thickness weekly (replace if ≤5mm); 3. Adjust alignment to ensure full contact with brake drum (no edge wear).

Why do the GB/T13781-1992 bearings on my JC28KIII wear faster than other bearings, and how to improve this?

GB/T13781-1992 bearings are used in high-contamination areas of the JC28KIII, so they wear faster due to mud/dust intrusion and humidity. To improve: 1. Clean bearing surfaces daily and check seals weekly; 2. Apply anti-rust grease quarterly (more often in coastal areas); 3. Replace grease every 6 months (use GB/T7324-2010 lithium-based grease). Genuine GB/T13781-1992 bearings have a corrosion-resistant coating—avoid non-genuine substitutes.

How to judge when to replace the mechanical seal and O ring (GB/T3452.1-1982) on JC28KIII?

For O rings (GB/T3452.1-1982): Replace every 3 months, or immediately if you see hardening, cracking, or oil leakage exceeding 3ml/24 hours. For mechanical seals: Replace if there’s continuous oil leakage (more than 10ml/24 hours), seal face scratches, or if the drawworks has dry-running incidents. Both parts are cheap but critical—delayed replacement causes expensive bearing/shaft damage.

What key standards and checks should I focus on when purchasing easy-worn parts for JC28KIII?

Focus on 3 key points for procurement: 1. Part Number Accuracy: Ensure parts match the original (e.g., GB/T276-64, JC28A-02-07)—no substitutes. 2. Standard Compliance: Bearings/seals must meet their respective GB standards (e.g., GB/T288-1994 for bearings), with a certificate of conformity (CoC). 3. Material Verification: Bearings use GCr15 steel, O rings use NBR rubber, brake blocks use asbestos-free friction material—avoid parts with unknown materials.